Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 127 insertions, 0 deletions

diff --git a/src/global/mail_open_ok.c b/src/global/mail_open_ok.c
new file mode 100644
index 0000000..a1bacad
--- /dev/null
+++ b/src/global/mail_open_ok.c
@@ -0,0 +1,127 @@
+/*++
+/* NAME
+/*	mail_open_ok 3
+/* SUMMARY
+/*	scrutinize mail queue file
+/* SYNOPSIS
+/*	#include <mail_open_ok.h>
+/*
+/*	int	mail_open_ok(queue_name, queue_id, statp, pathp)
+/*	const char *queue_name;
+/*	const char *queue_id;
+/*	struct stat *statp;
+/*	char	**pathp
+/* DESCRIPTION
+/*	mail_open_ok() determines if it is OK to open the specified
+/*	queue file.
+/*
+/*	The queue name and queue id should conform to the syntax
+/*	requirements for these names.
+/*	Unfortunately, on some systems readdir() etc. can return bogus
+/*	file names. For this reason, the code silently ignores invalid
+/*	queue file names.
+/*
+/*	The file should have mode 0700. Files with other permissions
+/*	are silently ignored.
+/*
+/*	The file should be a regular file.
+/*	Files that do not satisfy this requirement are skipped with
+/*	a warning.
+/*
+/*	The file link count is not restricted. With a writable maildrop
+/*	directory, refusal to deliver linked files is prone to denial of
+/*	service attack; it's better to deliver mail too often than not.
+/*
+/*	Upon return, the \fIstatp\fR argument receives the file
+/*	attributes and \fIpathp\fR a copy of the file name. The file
+/*	name is volatile. Make a copy if it is to be used for any
+/*	appreciable amount of time.
+/* DIAGNOSTICS
+/*	Warnings: bad file attributes (file type), multiple hard links.
+/*	mail_open_ok() returns MAIL_OPEN_YES for good files, MAIL_OPEN_NO
+/*	for anything else. It is left up to the system administrator to
+/*	deal with non-file objects.
+/* BUGS
+/*	mail_open_ok() examines a queue file without actually opening
+/*	it, and therefore is susceptible to race conditions.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System libraries. */
+
+#include <sys_defs.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <errno.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <warn_stat.h>
+
+/* Global library. */
+
+#include "mail_queue.h"
+#include "mail_open_ok.h"
+
+/* mail_open_ok - see if this file is OK to open */
+
+int     mail_open_ok(const char *queue_name, const char *queue_id,
+		             struct stat * statp, const char **path)
+{
+    if (mail_queue_name_ok(queue_name) == 0) {
+	msg_warn("bad mail queue name: %s", queue_name);
+	return (MAIL_OPEN_NO);
+    }
+    if (mail_queue_id_ok(queue_id) == 0)
+	return (MAIL_OPEN_NO);
+
+
+    /*
+     * I really would like to look up the file attributes *after* opening the
+     * file so that we could save one directory traversal on systems without
+     * name-to-inode cache. However, we don't necessarily always want to open
+     * the file.
+     */
+    *path = mail_queue_path((VSTRING *) 0, queue_name, queue_id);
+
+    if (lstat(*path, statp) < 0) {
+	if (errno != ENOENT)
+	    msg_warn("%s: %m", *path);
+	return (MAIL_OPEN_NO);
+    }
+    if (!S_ISREG(statp->st_mode)) {
+	msg_warn("%s: uid %ld: not a regular file", *path, (long) statp->st_uid);
+	return (MAIL_OPEN_NO);
+    }
+    if ((statp->st_mode & S_IRWXU) != MAIL_QUEUE_STAT_READY)
+	return (MAIL_OPEN_NO);
+
+    /*
+     * Workaround for spurious "file has 2 links" warnings in showq. As
+     * kernels have evolved from non-interruptible system calls towards
+     * fine-grained locks, the showq command has become likely to observe a
+     * file while the queue manager is in the middle of renaming it, at a
+     * time when the file has links to both the old and new name. We now log
+     * the warning only when the condition appears to be persistent.
+     */
+#define MINUTE_SECONDS	60			/* XXX should be centralized */
+
+    if (statp->st_nlink > 1) {
+	if (msg_verbose)
+	    msg_info("%s: uid %ld: file has %d links", *path,
+		     (long) statp->st_uid, (int) statp->st_nlink);
+	else if (statp->st_ctime < time((time_t *) 0) - MINUTE_SECONDS)
+	    msg_warn("%s: uid %ld: file has %d links", *path,
+		     (long) statp->st_uid, (int) statp->st_nlink);
+    }
+    return (MAIL_OPEN_YES);
+}